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Re: Proper /IRQ handling for multiple devices

Posted: Sat Aug 07, 2021 10:39 pm
by Dr Jefyll
BigDumbDinosaur wrote:
plasmo wrote:
To generate manual reset that stretches for the nominal 250ms, the reset button should connect to the VCC terminal of mcp130 and the VCC terminal should connect to 5V supply through a 1K or so current limiting resistor.

In other words, two parts are required to do the work of one. :D
In other words, you get to choose one priority (space saving) or another (cost saving), according to prevailing circumstances.

-- Jeff

Re: Proper /IRQ handling for multiple devices

Posted: Sat Aug 07, 2021 11:46 pm
by plasmo
OR...I can turn a deficit into a "feature": :D

I can connect the reset button directly to the reset line and have the option of either a debounced, 250mS long reset or a not debounced, not stretched reset. Why do I want a bouncy but deterministic reset? Because there is a tiny delay between the release of master reset and when a CF disk starts accessing its disk content. Some of my bootstrap-via-CF approach exploits that delay to hijack the bootstrapping to an alternative boot method. One of those "hit a key immediately after releasing reset" trick...
Bill

Re: Proper /IRQ handling for multiple devices

Posted: Sun Aug 08, 2021 12:56 am
by BigDumbDinosaur
Dr Jefyll wrote:
In other words, you get to choose one priority (space saving) or another (cost saving), according to prevailing circumstances.

Would you like fries with your burger, sir? :D

The cost vs. space dichotomy seems to be unavoidable everywhere one goes.